10 Nov 2020
BSAVA working with European Society of Veterinary Endocrinology after latter became aware of a permanent change in the antibody used for specific cortisol test.
Paul Imrie
Job Title
A dog with hyperadrenocorticism. Image © Ian Ramsey
The BSAVA is working with the European Society of Veterinary Endocrinology (ESVE) to inform vets of a change in the antibody used to test for cortisol.
The ESVE has been informed through its European Veterinary Endocrine Quality Assurance Scheme (EVE-QAS) of a permanent change in the antibody used for the Siemens Healthineers Immulite 2000, affecting the antibody pool from kit lot 550 onwards.
The change means it has already affected some laboratories, with others set to be impacted in the next few weeks or months. New antibody lots are being released to the US market, with other analysers unaffected.
Laboratories in the EVE-QAS have been quantifying the impact on results and reference limits.
An initial review by the EVE-QAS, based on more than 400 canine serum and more than 40 urine results, has suggested that canine serum cortisol results are lower (average bias -23% in canine serum) than diagnostic laboratories and clinicians have been used to in the past. The effect is more marked in canine urine cortisol (average bias -70%).
Since being alerted by the EVE-QAS, the manufacturer has derived mathematical adjustment factors that laboratories can incorporate into their systems to mitigate the impact on results. If the manufacturer adjustment is used then the results will be around 8% lower on average in serum and around 60% lower in urine.
Cut-offs to diagnose hyperadrenocorticism and rule out hypoadrenocorticism may need to be validated again with the new assay. Data in the EVE-QAS collaboration is not sufficient to assess the impact on feline and equine samples.
Ian Ramsey, BSAVA president and one of the founders of the ESVE, said: “Individual laboratories may have different ways of dealing with this change and, therefore, it is important to keep in touch with your laboratory provider concerning its approach.
“Some may choose to make the mathematical adjustments to results so that common and historic cut-off values can continue to be used. Others may report their results directly, but change their guidance on interpretative cut-off values.”
Both the BSAVA and ESVE are encouraging laboratories to tell clinicians which analyser they are using.
